DEST006486MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Date of registration: May 29, 1953 Advertised on June 14, 1956

GERMAN PATENT OFFICE

The invention relates to a process for the production of lubricating oil additives which lower the pour point by alkylating of aromatics.

It is known in lubricating oil technology that the properties of lubricating oils are reduced by adding them Sets of. To improve products that lower the pour point. In some cases it's technical and more economically advantageous to work with such additives than the oils instead more refined.

The solidification of lubricating oils at low temperatures is due to the formation of wax crystals. By removing the wax from the oil, one can therefore obtain oils with low pour points. For reasons of economy and quality, however, it is more advantageous to only partially remove the wax from the oil and to use additives to suppress the formation of crystals from the wax that has remained in the oil. It is assumed that the additive, which lowers the pour point, coats the wax crystals acting as nuclei and prevents their growth and thus the inclusion of the oil until a very low temperature of e.g. B. -29 to -34 ^{0 is} reached.

Alkyl aromatics with long paraffinic side chains have proven to be excellent pour point depressants proven. Alkylated naphthalene, phenol and similar compounds are listed as pour point

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humiliating extremely effective. The invention relates to the preparation of these alkylated ones Aromatics.

The alkylation of aromatics with paraffin compounds is known to take place by condensation with the aid of Friedel-Crafts catalysts. This Condensation can be carried out without a solvent; Usually, however, one works in Solvents, because you then have better control over the setting of the reaction conditions. Initially, light, preferably saturated aliphatic hydrocarbons were used as solvents, for example gasoline or luminous oil, which have the advantages of low cost and low responsiveness to have. However, since in this case oil-insoluble by-products are formed during the alkylation, one went to use the more expensive halogenated ones Hydrocarbons, such as tetrachloroethane or o-dichlorobenzene, are used as solvents.

The invention is based on the finding that you can use the chlorinated solvent with excellent Can replace results with a hydrocarbon oil whose viscosity is between about 1 and 47, is preferably between 30 and 43 cSt at 98.9 °.

These solvents are more accessible and give a product that is particularly strong in lowering the pour point Effect and excellent color. It also becomes costly and time consuming Solvent recovery avoided when using the volatile chlorine-containing solvents is required. The new process also eliminates the damage to health that occurs as a result the toxicity of chlorinated solvents. The following are those applicable according to the invention Reaction conditions described:.

The aromatic starting material

The material to be alkylated can be selected from a large number of aromatic compounds. In particular:

I. Non-substituted aromatics:

Benzene, naphthalene, diphenyl, phenanthrene, anthracene, pyrene, chrysene.

II. Substituted aromatics.

a) Hydrocarbon derivatives: toluene, xylene, indole, a-methylnaphthalene, / 3-methylnaphthalene, acenaph-

5P. Then, fluorene;

b) oxygen-containing derivatives: phenol, cresol,. Xylenols, α-naphthol, / 2-naphthol.

Of these compounds, naphthalene is preferred.

Alkylating agents

The alkylating agent can also be selected from a number of compounds. Examples' for this are:

I. Halogenated paraffins

If one works with a single halogen paraffin, it is essential that a considerable proportion of polyhalogenated molecules is present, thus chaining the aromatic Molecules takes place in the required proportions and a product of the desired molecular weight is obtained. In theory, the polyhalogenated molecules should be on each terminal group contain a halogen atom. However, very good results are also achieved if one or two of the Halogen groups are secondary groups.

A mixture of haloparaffins can also be used; however, the polyhalogenated Molecules must be present in substantial proportions in order to obtain the desired chain formation. Those haloparaffins which have 8 to 30 carbon atoms, preferably in straight chain, although a small branching of the chain is allowed. examples for Usable halides are the normal or isooctyl halides, the decyl halides, the lauryl halides, the octadecyl halides, etc .; they are used individually or in combination. The chlorides are preferred in all cases, although the corresponding bromides and iodides are also used can. Halogen derivatives of a mixture of hydrocarbons, such as paraffin wax, mineral fat (petrolatum), or mineral oil distillates in the form of halogenated hydrocarbon oils, e.g. B. heavy fuel, light oil, Gas oil, lubricating oil fractions and the like are usable.

II. Olefins

Olefins can also be used as alkylating agents in the process according to the invention. The olefin in question can be one of the known olefins having 8 to 30 carbon atoms, which are preferably are tied in a straight chain. Olefins produced by elimination of water from alcohol or elimination of hydrogen halide arise from primary halides or from the heat splitting of hydrocarbons are very useful as alkylating agents. One can also use the olefins produced by Hydrocarbon synthesis, through the addition of 2 hydrogen atoms to an acetylene compound or obtained by polymerizing single or mixed olefins. Of course you can too Use mixtures of the various olefins, as well as diolefins with conjugated ones. or non-conjugated Double bonds, individually or in admixture with monoolefins.

Preferred olefins are those in which the double bond is on the terminal carbon atom. However, the double bond can also be located at any other point in the chain, provided that there is a relatively straight chain of 8 to 25 carbon atoms between this double bond and the next double bond or the end of the chain.

Those olefins that are produced by thermal cleavage of wax or mineral fat are particularly valuable be won. These - olefins contain a high percentage of abnormal olefins with 14 to 24 carbon atoms in a straight chain.

Of the various alkylating agents mentioned. are chlorinated. Paraffin waxes with 20 to

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30 carbon atoms in an essentially straight chain preferred, which up to a chlorine content of 8 to 30, preferably 14 to 25 percent by weight are chlorinated. . ■

The catalyst

The known Friedel-Crafts catalysts can be used for the condensation. They are added to the reaction mixture in the form of a powder or a complex with a short chain alkyl halide such as methyl chloride. As usable are z. Examples include: AlCl ₃ , AlBr ₃ , AlBr ₂ Cl, AlClBr ₂ , Al ₂ Br ₅ Cl, ZnCl ₂ , BF ₃ and the like, of which AlCl _{3 is} preferred.

working conditions

Depending on the starting material and the desired properties of the end product, one can choose from work in different conditions. In general, the alkylation time according to the invention is 2 to 8, preferably 4 to 6 hours.

Suitable reaction temperatures are in the range from 24 to 149, preferably 38 to 79 °.

The proportions of the reactants can be 0.3 to 5, preferably 1 to 3 mol of alkylating agent / mol aromatic hydrocarbon.

solvent

The essence of the invention lies in the use of a hydrocarbon oil with a viscosity of 1 to 47, preferably from 30 to 43 cSt at 98.9 ° as a solvent for the reaction.

The following examples serve to explain the invention further.

example 1

506 kg of bright stock lubricating oil obtained from a panhandle crude oil and having a viscosity of 32 cSt at 98.9 ° were introduced into a glass-lined Pfaudler reaction vessel with a capacity of about 75701. Then 272 kg of naphthalene was added. The temperature was now set to 32 ⁰ , whereupon 52 kg of aluminum chloride were added. The temperature rose to 34 °. In the course of an hour 2302 kg chlorinated wax containing 14.5 ° / ₀ of chlorine were continuously added. The temperature was allowed to rise to 47 °.

Then was slowly warmed to 52 ⁰ and the overall temperature is maintained for 4 hours after 'completion of the addition of the chlorine wax at this level.

After 2 to 3 hours, samples were taken and the catalyst with alcohol and aqueous Caustic soda destroyed.

After a reaction time of 4 hours the entire reaction mixture with 1427 kg mineral oil having a viscosity of 8.7 cSt at 98.9 ° was diluted, the catalyst with isopropyl alcohol and aqueous sodium hydroxide solution destroyed, the catalyst layer is removed and the product with heating to 282 ⁰ with steam distilled off.

In the samples taken after 2 and 3 hours and a sample of the finished reaction product, the yield was determined, ie the amount by weight of technical pour point depressant obtained from a unit weight of unchlorinated wax. In addition, parts of the samples were diluted with Varsol, a white spirit in the boiling range from 150 to 200 °, to a concentration of 25 ° / ₀ and then the color value according to Robinson was determined. This test is detailed in "New and Revised Tag Manual for Inspectors of Petroleum", p. 57, test number 3,. "Color of Lubricating Oils by the Tag-Robinson Colorimeter", 26th edition, 1942, described. Yields and Robinson color values for pour point lower commercial starch produced from these samples are given in Table I.

Table I.

Rehearsal, after hours Color value
after
Robinson yield 2
3
4 (end product) 9.75
8.75
9.5 3.4
4.9
5.2

Table II

Rehearsal, after hours Color value according to
Robinson yield 2
3
4th
5
6 (final product) 5
6th
4.5
5.2
6.0 5.4.
5.6
5.6
6.0
4.7

It can be seen that the yield increases with the duration of the reaction, and that the color value of the The final product of 9.5 Robinson is extremely satisfactory, while the color values of the Products using chlorinated solvents are 3 to 4.

1 example 2

Since the yield in the experiment described above (2 to 4 hours reaction time) is continuous increased, a second test was carried out according to Example 1, but with the following changes:

1. The temperature was allowed during the addition of the chlorinated wax 54 ⁰ increase.

2. The reaction was continued 6 hours after the chlorine wax had been added, in order to reduce the to determine the best response time.

3. Samples were taken after 2, 3, 4 and 5 hours. . .

Table II contains the data for the Robinson color value of a 25% solution in a ^{white spirit in the boiling range from 150 to 200 0} and the yields of pour point depressants of commercial starch from these samples:

These values show that the yield is up to a reaction time of 5 hours after the addition

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of chlorine wax increases and then begins to decrease again. Thereafter, the most favorable reaction time is 3 to 5 hours.

Example 3

The pour point depressant produced from the product according to Example 2 in a commercially available form was mixed with two test oils in varying amounts and the ASTM pour point of the mixtures determined to determine the pour point lowering effectiveness of the agent.

Oil A was a paraffin distillate refined with sulfuric acid (viscosity 4.6 cSt at 98.9 °).

Oil B was a 1: i mixture of Oil A and one Pennsyivania bright stock oil (viscosity 32 cSt at 98.9 °).

Table III

Flow points, ⁰ C
Weight percent additive | Oil A

Oil B

none - 1.1 - 1.1 0.09 - 15.0 - 12.2 0.15 - 17.8 - 23.3 0.23 - 23.3 - 23.3 0.38 - 28.9 - 28.9 o, 75 - 34.4 - 3! .7

These values show that the invention product prepared> superior efficacy has fließpunkterniedrigende by 0.75 ° / ₀ of the additive reduces the set flow point in the oils A and B of 33.3 or 30.6 °.

Example 4

Pour point depressants tend to reduce their effective

in lubricating oils if the oil mixture is exposed to strong temperature fluctuations. Such additives are said to be inconsistent because they provide inconsistent pour points. It became a Process developed to reduce this loss of pour point Determine the effectiveness of the various lubricating oil additives. This test is called the »S. 0. D. Pour Stability Test «. He is in detail in the "SÄE Quarterly Transactions", Vol. 12, No. ι (January 1948), pp. 34 to 44, described. During this test, the mixture is quickly cooled to -9.4 °, whereupon it is reduced to + i, i ° lets warm up and holds at this temperature for 24 hours. The mixture is then further to + 10 ° heated and at a rate of o, 56 ° / h.

cooled to - 28.9 °. The point at which the mixture solidifies after this temperature cycle, is referred to as the stable solid point.

The product prepared according to Example 2 was added in various percentages to a base oil which had a viscosity of 5 cSt "at 98.9 °, a pour point of -1.1 ° and a stable solidification point of -6.7 °. The mixtures were subjected to the "S. OD Pour Stability Test", the values given in Table IV being obtained. For comparison purposes, a product prepared by the previously customary process was used, ie a product in which o-dichlorobenzene was used as the solvent in the preparation.

Table IV
SOD Pour Stability Test

Weight percent additive More stable
Freezing point, ° C (Oil as a solvent) 0.14 - 20.0 0.28 - 26.1 0.56 - 23.3 (o-dichlorobenzene as a solvent). ^s 0.14 - 6.7 0.28 - 6.7 0.56 - 6.7

Parts by weight of solvent
100 parts chlorine wax

15th
20th
20th
25th

3.9

5.3

5.9

4.4

These values show that the additives produced according to the invention have an outstanding stability, when exposed to temperature fluctuations.

Example 5

To determine the effect of the amount of solvent on the process, using different amounts of the solvent worked according to Example 2 and the yields of the end product definitely. These values are given in Table V.

Table V
Effect of the amount of solvent

These values show that when using S 15 to 25 parts of solvent are chlorinated per 100 parts Wax achieves high yields, but the optimum is 20 to 25 parts of solvent per 100 parts chlorinated wax lies.

Example 6

To show the usability of various hydrocarbon oils as solvents and the To determine the viscosity range suitable for this, laboratory tests were carried out in accordance with the example 2 carried out, only the hydrocarbon oil was changed. It became the

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Yields of end product determined. The following values were obtained:

Table VI

Influence of the solvent used
Hydrocarbon oil

viscosity Viscose yield
to "PlipR- origin at 98.9 °
cSt activity
index OjLX X ¹ Ii-CJ * '
Point
humiliating i. Louisiana Crude Oil 5.5 113 2, O 2. Coastal crude oil ... 8.5 84 2.0 3. Pennsylvania crude oil 5.7 IOO 2.0 4. Pennsylvania Crude oil. ..: QQ 2.4 5. Coastal Crude Oil ... 3.5 73 2.8 6. Louisiana Crude Oil 2.0 109 2.8 7. Coastal Crude Oil ... 5, i 75 3.2 8. Louisiana Crude Oil 9.4 103 3.5 9. Coastal Crude Oil ... 42.0 75 4.9 10. Panhandle Crude Oil 34.9 98 4.3 11. Panhandle Crude Oil ■ 3i, 8 100 5, o

These values show that although distillates can be used, their viscosity is in the range at 98.9 ° from ι to 47 cSt, but that distillates with a viscosity of 30 to 43 cSt are to be preferred because they give the highest yields.

The alkylated aromatics made in accordance with the present invention are excellent pour point depressants for waxy mineral lubricating oils. The amount of additive varies slightly depending on the one used Basis and the desired end product. Mixtures containing 0.02 to 10 percent by weight of the additive contain, have very low pour points; a range of 0.1 to 5 percent by weight is preferred.

It is common in lubricating oil technology to use lubricating oil additives in the form of concentrates in oil. These concentrates can be more economical ship and handle, and the lubricant manufacturer only needs the base oil add the calculated amount of concentrate to produce the desired finished product. Such Oil concentrates of the products produced according to the invention can contain 10 to 80 percent by weight of additives contain.

The base oils provided with the pour point depressants according to the invention can of course contain other additives, such as extreme pressure additives, viscosity index improvers, oxidation retardants, Sludge inhibitors, demulsifiers, rust inhibitors, corrosion inhibitors and the like are all of these Agents are compatible with the pour point depressants produced according to the invention.

Claims (3)

Patent claims: 1. A process for the preparation of alkylaromatic pour point-lowering lubricating oil additives, thereby characterized in that one uses an aromatic hydrocarbon according to Friedel-Crafts halogenated aliphatic compounds of about 8 to 30 carbon atoms in a straight chain in Alkylated in the presence of a hydrocarbon oil whose viscosity at 98.9 ° is between 1 and 47 cSt located. 2. The method according to claim 1, characterized in that that the alkylation in the presence of 15 to 30 parts by weight of a hydrocarbon oil from the viscosity of 30 to 43 cSt at 98.9 ° per 100 parts by weight of the halogenated aliphatic hydrocarbon performs. 3. The method according to claim 2, characterized in that the aromatic hydrocarbon mixes with the hydrocarbon oil, the Friedel-Crafts catalyst and then 0.3 to 5 moles of the halogenated hydrocarbon per mole of aromatic hydrocarbon added, the temperature increased to 38 to 60 ° and held at this level for 2 to 6 hours and finally the alkylated separating aromatic compounds from the reaction mixture. Referred publications:
French Patent Nos. 915 459, 942 080, 082; U.S. Patents Nos. 2,465,610, 2,521,344, 526 490. © 609 530/463 6. 56